Roxbury in Litchfield County, Connecticut — The American Northeast (New England)

Mine Hill Preserve

A place of Natural, Geologic and Industrial Heritage

By Michael Herrick, June 22, 2009

1. Mine Hill Preserve Marker

Inscription. Recognized on the National Register of Historic Places, Mine Hill is the site of a 19th century iron mine and furnace complex. The Roxbury Land Trust acquired the 360-acre preserve in 1978. The significant stone and brick structural remains of the furnace complex have been restored and stabilized. These historic structures are located 0.2 miles from where you stand. At the complex, you will also find three groups of interpretive signs which explain Mine Hill’s history, the iron-making process and Mine Hill’s impact on the region.

A trail loop (blue blazes) runs along the perimeter of the preserve with a distance of 3.5 miles. Clockwise, this trail ascends up the Donkey Trail and passes by two mine tunnels and a series of grated air shafts, which now serve as entryways to several bat hibernacula. The trail then begins its descent past an abandoned quarry. It eventually joins a dirt road (Hodge Road) and ends at the furnace complex.

For a shorter hike, there is an easy trail around the reservoir located about 100 yards from the base of the Donkey Trail. This trail begins at the base of the reservoir, crosses over the earthen dam and bridge, loops around the reservoir and then rejoins the Donkey Trail.

Erected by Roxbury Land Trust.

Location.

By Michael Herrick, June 22, 2009

2. The Blast Furnace and Chimney

41° 33.589′ N, 73° 20.121′ W. Marker is in Roxbury, Connecticut, in Litchfield County. Marker can be reached from Mine Hill Road half a mile from Hodge Road. Touch for map. Marker is about 0.2 miles from the parking lot on the trail to the blast furnace. Marker is in this post office area: Roxbury CT 06783, United States of America.

Once known as Spruce Hill and set aside as “common land” because it was too steep and rocky even for hardscrabble Yankee farmers, Mine Hill gave rise to a thriving industrial center in the late 1860’s. Fortunes were made and lost on the rich veins of quartz, siderite and granite that cut through the wooded slope. The mines spawned a bustling boom town called Chalybes and employed hundreds of immigrant workers.

At their height, the iron mines produced 10 tons of pig iron per day. Whole forests were cut down to make into charcoal to fuel the furnaces at the mines. Despite substantial initial investment and elaborate planning, the steel-making operation was plagued by problems from the outset. Just five years after the enterprise began, the furnaces hut down. The granite quarries, however continue to flourish to this day.

Purchased by the Roxbury Land Trust in 1978, Mine Hill became a National Historic Landmark a year later. Today, the forest has reclaimed the land and healed most of the scars on the 360-acre preserve, but the remains of the mine and furnaces stand as a reminder of our industrial heritage.

By Michael Herrick, June 22, 2009

4. Mine Hill During Its Heyday

Roxbury’s experiment with the iron and steel industry was short, but intense. The Shepaug Spathic Iron and Steel Co. greatly expanded the extraction of ore at Mine Hill in 1865 with $300,000 in capital. A Donkey Trail was built to provide access to multiple mines nearly a mile up the hillside and before long, a pair of roasting ovens, a blast furnace, a steel puddling furnace, a rolling mill and more than a half dozen buildings crowded a gentle slope at the base of the hill.

When the smelter formed a “salamander” at its first firing in 1867, the company had to be refinanced with $1 million and was renamed the American Silver Steel Company. That company moved the steel-making to Bridgeport before it reorganized and changed its name to the Shepaug Iron Company in 1872. An attempt to change the smelter from cold to hot air blasting to improve its efficiency also failed that year

By Michael Herrick, June 22, 2009

5. Cold Blast Furnace

Feeding America’s Demand For Iron

Meticulously restored in the early 1980s, the cold blast furnace that stands before you was at the heart of the Mine Hill iron-making venture. The structure was built of Roxbury granite and would have been topped by a tall chimney. A bulb-shaped “bosh” formed the core of the furnace and arches in the base of the furnace provided access to the crucible.

Alternating loads of charcoal, roasted siderite and either limestone or marble were dumped from the charging platform into the top of the furnace through a large opening in the chimney. On the way down the fiery stack, the carbon in the charcoal combined with the oxygen in the iron ore and escaped as gas, leaving the iron behind. A continuous blast of air generated by steam engines in the power house and blown into the furnace through the “tuyere” pipes kept the fire roaring at 3,000şF around the clock.

Over time, the ore melted and sunk down to the crucible at the base of the bosh. The lime in the mixture acted as flux, which separated the impurities from the melted iron. The resulting “slag” floated on top of the iron and was later discarded as waste. When the furnace master decided the time was right, he broke off a clay plug that allowed the molten metal to flow out of the hearth into runners dug in the sand floor of the casting room. Here, it cooled to form the iron bars known as pigs. The furnace was tapped up to six times a day.

By Michael Herrick, June 22, 2009

6. The Quarries

Prospering Through the Years with Roxbury Granite

While the fortunes of the mines at Mine Hill rose and fell over the years, eight granite quarries at the site prospered and have brought a steady income for their owners for close to two centuries. In fact, when Yale University professor Benjamin Sillman visited Roxbury in 1817, he was more impressed by the “light, agreeable gray” stone he found than the iron and silver ore, declaring the granite “singularly perfect.”

It is not clear when quarrying at Mine Hill first began, but it seems likely that stone was being cut by individuals on an informal basis long before 1850 when records suggest the first quarry opened. Oxcarts carried the granite to Roxbury and New Milford for use as door steps and foundations. When the railroad came to Mine Hill in 1871, the granite stones were transported as far away as New York and New Britain for use in building churches, bridges and fine homes.

In 1899, Roxbury’s Charles Hodge and his partners established the Mine Hill Quarry Company to work the Rockside Quarry (lower quarry), which had opened at the foot of Mine Hill nearly a decade earlier. Although the upper quarry closed down around 1905, the lower quarry operated for another 30 years before closing. In the 1950s, quarrying resumed in both the upper and lower quarries with the help of more modern equipment and trucks. Quarrying continues to this day at Mine Hill, with the fine Roxbury granite prized for building hearths, chimneys, terraces and other structures.

By Michael Herrick, June 22, 2009

7. Chalybes and the Railroad

From Bustling Roxbury Station to Vanished Town

With Roxbury’s mines and quarries bustling in the late 1860s, a community quickly grew at the base of Mine Hill. Named Chalybes for ancient tribes of ironworkers, the enclave consisted of at least a dozen buildings ranging from a creamery to a lumber yard and even had a footbridge over the Shepaug River.

The hundreds of workers who settled at Chalybes were mostly immigrants from Poland, but there were also skilled stone cutters, masons and other laborers from Ireland, Sweden, Germany and Italy. These newcomers brought rich new cultures to Roxbury, which consisted largely at the time of second and third-generation farmers of English Stock.

Roxbury also became connected to the wider world in 1871 when the Shepaug Valley Railroad from Hawleyville to Litchfield opened a station in Chalybes. The train came too late to help the iron and steel operation, but Roxbury granite, silica, milk and other products soon started being shipped to markets as far away as New York City.

As mining and other industries in the area began to slow down, Chalybes gradually lost its population and became known as Roxbury Station. Today, all that remains of this vanished town at the intersection of Route 67 and Mine Hill Road are the general store, the cigar factory and the railroad station – all now converted to private homes or businesses.

By Michael Herrick, June 22, 2009

8. From Ore to Steel

The Steel-Making Process at Mine Hill
Mining
Miners used hand tools to drill into the hard granite rock, filled the drill holes with powder and blasted the rock loose. Working by candlelight in the resulting tunnels, the miners then excavated the ore and loaded it into ore carts.
Transporting
The loaded ore carts were moved on 24-inch gauge rails, which ran downhill from the entrance of the lowest tunnel to the roasting ovens. The empty carts were pulled back uphill by donkeys on the elevated pathway above where you are standing.
Roasting
The first step in processing the Mine Hill siderite was to heat the ore in one of two large ovens. This “pre-roasting” drove off some of the carbon and sulfur contained in the ore, which otherwise may have caused problems in the blast furnace.
Sorting
The roasted ore was brittle and easy to separate by hand into piles of iron oxide and unwanted quartz. Once sorted, the ore was moved down the charging ramp – an enclosed platform reaching from the roasting ovens to the top of the blast furnace. On its way to the furnace, the ore was crushed and mixed with pieces of marble or limestone, which acted as flux.
Charging
Workmen the “charged” the blast furnace, shoveling alternate loads of prepared ore and charcoal into the top of the furnace. As the ore and charcoal worked their way down into the furnace, the intense heat from the burning charcoal transformed the ore into molten metal.
Casting
When the crucible (lowest part) of the furnace became full, impurities called “slag” were drawn off the top through a hole in the side of the furnace. The molten iron was tapped through a hole lower down in the side of the hearth and ran into channels in a sand casting bed, where it cooled into iron pigs.
Making Steel
Although plans called for converting the pig iron into steel using the “puddling” technique perfected in Prussia and Austria, very little steel was actually made in Roxbury. Steel production ended at Mine Hill on February 25, 1868, shortly after the first run of the puddling furnace. By autumn, the steel mill was dismantled and moved to Bridgeport. Oxcarts then carried the pig iron to New Milford, where it was transported by rail to Bridgeport.

By Michael Herrick, June 22, 2009

9. The Mines

A Labyrinth of Tunnels Beneath Mine Hill

A Labyrinth of more than a half mile of tunnels exists to this day below the wooded slope of Mine Hill. There are three main tunnels connected by multiple interior vertical shafts or “stopes.” These shafts not only provided air for the miners, but also for movement of the ore. Although all three tunnels eventually had rails inside them, only the tunnel closest to the bottom of the hill connected to the Donkey Trail. Consequently, workers dropped the ore from the two top tunnels down to the lower tunnel and reloaded it into ore carts for transport to the roasting ovens.

Initially, miners found veins of the iron and dug trenches to follow the veins. As the trenches grew, miners were probably lowered down by a windlass, and buckets of ore were hoisted back out. Later, miners dug the horizontal tunnels and laid rails for easier transport of the ore. A series of ladders connected the mines, and wax candles in iron holders lining the tunnels and shafts provided the only source of light.

Many “drifts” or side tunnels exist where workers dug in all directions to follow veins until they ran out, even building platforms and tunneling upward when necessary. Today, two tunnel entrances remain visible from the trail.

By Michael Herrick, June 22, 2009

10. The Donkey Trail

Linking the Mines to the Manufacturing

Mine Hill’s Donkey Trail was built between 1865 and 1867 to link the iron mines to the smelting complex nearly a mile below via a narrow-gauge railway. At the mouth of the lower tunnel, workers cut the trail into the hillside. Further down the hill, they painstakingly built an elevated tramway of double fieldstone walls filled with smaller rubble. The resulting 6-foot-wide elevated platform helped keep the tracks at a level and steady grade.

A single 24-inch-gauge track was laid along the path. No records exist, but logic suggests that loaded ore carts would travel down the path with a brakeman slowing their progress. After the ore carts were unloaded at the roasting ovens, donkeys would pull the empty carts back up the hill into the mines.

Today, the Donkey Trail stands in remarkably good condition and serves as an excellent walking trail to the mines. It offers hikers glimpses of more than 25 species of hardwood trees that grow on Mine Hill and passes under majestic stands of hemlocks.

By Michael Herrick, June 22, 2009

11. Front of the Roasting Ovens

By Michael Herrick, June 22, 2009

12. Top of the Roasting Ovens

Credits. This page was last revised on June 16, 2016. This page originally submitted on July 5, 2009, by Michael Herrick of Southbury, Connecticut. This page has been viewed 1,994 times since then and 27 times this year. Photos:1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12. submitted on July 5, 2009, by Michael Herrick of Southbury, Connecticut. • Syd Whittle was the editor who published this page.